IDE Transfer rate

[TalShiar]

If you have a ATA133 mobo with one primary HD at ATA133 and a secondary at ATA100 are they both limited to ATA100?
If you have a link to the answer to this it would be great.

 

[Lord Evermore]

They'll both run at their own rated speeds (other than the inherent problem of IDE, in which only one device can actually send/receive on the same channel at a time). The original ATA33 and ATA66 chipsets had an issue with this I believe, where the drives would only run at the lowest specification device, but that's been resolved for some time now. I don't have a link specifically to it though, since it's the way everything works now, nobody lists "independent device mode" in specs anymore, and I don't have any real technical white papers handy for the Ultra-ATA specs.

This AT FAQ mentions independent device timing as being standard in all current chipsets, but doesn't give an "authoritative" page about it.

Finally found this page at Storage Review that mentions independent timing. One thing that I know for a fact is wrong (and may depend on chipset, and have been correct when that was written) is the mention that PIO can't be used on the same channel as DMA. I've installed Windows 2000 and had it run the primary slave CD drive at PIO mode while the primary master hard drive was in DMA mode 4 or 5. In one case it was due to Windows apparently just defaulting to that as a precaution since not all CD drives support DMA mode, and I was able to simply specify to use DMA mode if available. In another case, the drive really didn't support DMA mode, and everything continued to work fine with independent speeds.